Facts in The Night Climb
Each claim in the narration, its source and the wording it rests on. Read 2026-10-31.
| Line | Claim | Source | Wording / note |
|---|---|---|---|
| 1 | Half a kilometre down at sunset | Wikipedia, "Lanternfish", https://en.wikipedia.org/wiki/Lanternfish | most species spend the day "between 300 and 1,500 m" deep and rise toward the surface at sundown. 500 m is inside that range; depths vary widely between species. |
| 2 | No longer than your finger | same | lanternfish range "from about 2 to 30 cm", most under 15 cm. True for most species (a finger is about 7–8 cm), not for the largest. |
| 3 | Climbs toward the surface in the dark | same | "towards sundown, the fish begin to rise into the epipelagic zone" (roughly 10–100 m). |
| 6–7 | Belly lights as bright as the glow above hide the shadow | same | ventral photophores serve as "counterillumination to camouflage their silhouette when viewed from below"; the fish adjust the brightness of the bluish light to match the light from above. |
| 10–11 | Every night countless animals rise from the deep; the largest migration on Earth | Woods Hole Oceanographic Institution, Ocean Twilight Zone, "Greatest Migration on Earth Happens under Darkness Every Day", https://twilightzone.whoi.edu/greatest-migration-on-earth-happens-under-darkness-every-day ; Scientific American, same title, https://www.scientificamerican.com/article/greatest-migration-on-earth-happens-under-darkness-every-day | the daily vertical migration is described as the greatest migration on Earth; sources usually measure it by biomass, some by number of animals. The narration does not say which. |
| 12 | They sink back before sunrise | same | the migrants return to depth by day. |
Storytelling, not fact: the hunter is not named (drawn after the deep-sea dragonfishes: fangs, a chin lure, a red light under the eye); its ambush at this depth is staged. A climb of hours is compressed into seconds, and the depth figures on screen are illustrative.